Vancomycin is a glycopeptide antibiotic represented by the following structural formula (I):

Vancomycin is used in the prophylaxis and treatment of infections caused by Gram-positive bacteria. Vancomycin is used in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-susceptible Staphylococcus aureus (MSSA), and to treat patients who are penicillin-resistant. Vancomycin HCl is commercially available inter alia, as a frozen premixed formulation, which can be used for intravenous administration after thawing.
Vancomycin exhibits premature degradation after reconstitution of the lyophilized product. Vancomycin is stable in water for approximately 24 hours after reconstitution, and is therefore, not suitable for long-term storage in liquid form. There is a need for vancomycin formulations with increased stability. One solution to this to addresses this need is described in US Patent Application Publication No. 2016/0101147, the contents of which are incorporated herein by reference. This patent application discloses vancomycin formulations containing propylene glycol and/or polyethylene glycol. However, further innovations have been sought for certain patient populations, such as children or renally impaired patients where it may be advantageous to avoid propylene glycol and or PEG in intravenous products. Therefore, there is a continued need for new liquid vancomycin formulations with sufficient stability that can be delivered to patients.
It is generally known that vancomycin has a tendency to increase substantially in viscosity, for example to gel, at higher concentrations. It has also been disclosed that alcohols may be used for the reduction of this formation as noted in U.S. Pat. No. 4,885,275. However, glycerol (aka glycerine) did not prevent the formation of this gelation (see Table 1 therein, which noted that glycerine did not prevent the gelation of the vancomycin preparation). The '275 patent therefore teaches away from the use of glycerol in vancomycin compositions requiring lower viscosity.